LTE-V2X Mode 3 scheduling based on adaptive spatial reuse of radio resources
LTE-V2X (also known as C-V2X or Cellular V2X) introduces direct or sidelink V2V (Vehicle to Vehicle) communications using the PC5 interface. LTE-V2X defines two modes (Mode 3 and Mode 4) for the management of radio resources. This study focuses on Mode 3 where the cellular network manages and allocates the radio resources for direct or sidelink V2V communications. Contrary to Mode 4, the 3GPP standards do not define any concrete scheduling scheme to allocate resources under Mode 3. In this context, this paper proposes a context-based scheduling scheme for LTE-V2X Mode 3 that exploits the geographical location of vehicles and dynamically configures its operation with the objective that all vehicles experience a similar level of interference when resources must be shared. The proposed scheduling scheme, referred to as DIRAC (aDaptive spatIal Reuse of rAdio resourCes), is validated analytically and its performance is evaluated through system level simulations. The evaluation shows that DIRAC outperforms existing LTE-V2X Mode 3 and Mode 4 scheduling schemes and ensures a more scalable and stable network operation as the channel load and congestion increases.